Damage mechanism assessment method and system based on mixed-flow water turbine

Abstract

The invention belongs to the technical field of hydropower station equipment detection and evaluation, and particularly discloses a damage mechanism evaluation method and system based on a mixed-flow water turbine. The method comprises the steps of firstly collecting original data of a water turbine under different working conditions, and obtaining influence factors of the working conditions from the original data; a water turbine operation test is conducted, the change relation between the influence factors and the performance indexes under the normal working condition is obtained, significance analysis is conducted on the influence factors based on the change relation, and significant factors are obtained; a simulation model of the water turbine is established, the value of the significant factor is adjusted for multi-physical field simulation analysis, the damage condition of the water turbine is extracted from simulation data, and the value of the significant factor and the corresponding damage condition are stored in an evaluation database. And finally, obtaining the value of the significant factor during operation of the to-be-evaluated water turbine in real time, and comparing and matching the value of the significant factor with the evaluation database to obtain the damage condition of the to-be-evaluated water turbine. Compared with an existing damage assessment method, the scheme of the invention is faster and more accurate.

Description

Technical Field

[0001] The present application belongs to the technical field of hydropower station equipment detection and evaluation, and more specifically, to a damage mechanism evaluation method and system based on a Francis turbine. Background Art

[0002] As my country's industrialization advances, energy is a key element in the development of industrialization. Francis turbines, as the core equipment for hydropower generation, are widely used in hydropower stations around the world because of their high efficiency and wide range of applications. In actual operation, Francis turbines face complex and changeable operating conditions, such as wide load operation, changes in water flow velocity, material fatigue, etc. These factors act together on various components of the turbine. The runner, as the core component for converting water energy into mechanical energy, needs to withstand huge hydrodynamic loads and alternating stresses during operation, which may cause fatigue cracks and cavitation damage to the blades, seriously affecting the safe and efficient operation of the unit. Therefore, it is particularly important to conduct real-time assessment of Francis turbine damage in pumped storage.

[0003] At present, the commonly used damage detection and assessment of Francis turbines has a complex process and a large workload, making it difficult to quickly and accurately assess the damage of the turbine, resulting in the inability to make reasonable diagnosis and maintenance of the turbine in a timely manner. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a damage mechanism assessment method and system based on a Francis turbine, which aims to solve the current technical problem that it is difficult to quickly and accurately assess the damage status of a Francis turbine.

[0005] To achieve the above objectives, in a first aspect, the present application provides a damage mechanism assessment method based on a Francis turbine, the damage mechanism assessment method comprising: Collect the original data of the turbine under different working conditions and obtain the influencing factors of the working conditions from the original data; Conducting a turbine operation test to obtain the changing relationship between the influencing factors and the performance indicators under normal working conditions, and performing a significance analysis on the influencing factors based on the changing relationship to obtain significant factors; Establish a simulation model of the turbine, adjust the value of the significant factor to perform multi-physics field simulation analysis, extract the damage of the turbine from the simulation data, and save the value of the significant factor and the corresponding damage to the evaluation database; The values ​​of significant factors of the turbine to be evaluated are obtained in real time during operation, and the values ​​of significant factors are compared and matched with the evaluation database to obtain the damage status of the turbine to be evaluated.

[0006] Preferably, a turbine operation test is performed to obtain the changing relationship between the influencing factors and the performance indicators under normal working conditions, specifically: Under the premise of ensuring the normal operation of the turbine, the value of the influencing factor is used as the experimental input, and the performance index of the turbine is used as the experimental output; Each time, the test input is changed with a preset step size, and the test is repeated until all influencing factors are input, and each test input and corresponding test output are recorded; Use mathematical models to describe the changing relationship between influencing factors and performance indicators.

[0007] Preferably, a significance analysis is performed on various influencing factors based on the change relationship to obtain significant factors; Determine the influencing factors that have a significant impact on the performance indicators according to the significance level; Ranking the impact factors with significant influence based on their impact size; The influencing factors with the greatest impact are defined as significant factors.

[0008] Preferably, the influencing factors include blade inclination angle, guide vane opening, water flow velocity and water head height.

[0009] Preferably, the performance indicators include work efficiency, hydraulic loss and vibration noise.

[0010] Preferably, the evaluation database further includes: selecting significant factors from the original data, extracting damage conditions of the turbine from the corresponding original data, and saving the values ​​of the significant factors and the corresponding damage conditions to the evaluation database.

[0011] Preferably, the damage condition is obtained specifically by the following method: obtaining the pressure distribution, temperature distribution and water flow distribution when the turbine is running; and evaluating the damage location and degree of the turbine based on the pressure distribution, temperature distribution and water flow distribution.

[0012] Preferably, the simulation data specifically comprises: comparing the simulation data with the original data, and retaining the simulation data whose difference is less than a preset threshold.

[0013] Preferably, a turbine operation test is performed on the turbine to be evaluated; and a simulation model of the turbine is established using the turbine to be evaluated as a template.

[0014] In a second aspect, the present application provides a damage mechanism assessment system based on a Francis turbine, the damage mechanism assessment system comprising: A data collection module is used to collect raw data of the turbine under different working conditions and obtain the influencing factors of the working conditions from the raw data; The test analysis module is used to conduct a turbine operation test, obtain the change relationship between the influencing factors and the performance indicators under normal working conditions, and perform a significance analysis on the influencing factors based on the change relationship to obtain significant factors; The simulation analysis module is used to establish a simulation model of the turbine, adjust the value of the significant factor to perform multi-physics field simulation analysis, extract the damage of the turbine from the simulation data, and save the value of the significant factor and the corresponding damage to the evaluation database; The damage assessment module is used to obtain the values ​​of significant factors of the turbine to be assessed in real time during operation, compare and match the values ​​of the significant factors with the assessment database, and obtain the damage status of the turbine to be assessed.

[0015] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: (1) The damage assessment method of the present application is to obtain the damage condition of the turbine by matching the actual operation data of the turbine with the assessment database, wherein the assessment database stores the mapping relationship between the operation data and the damage condition. This method is faster and more accurate than the existing damage assessment methods.

[0016] (2) This application maps the damage condition of the turbine based on the significant factors that are most sensitive to changes in the turbine's operating conditions. This solution can ensure the accuracy of the damage assessment, while greatly reducing the parameters that require attention and reducing the size of the assessment database.

[0017] (3) This application expands the evaluation scope of the evaluation database through simulation experiments, and also uses the original data to eliminate inaccurate simulation data, thereby ensuring the accuracy of the simulation data in the evaluation database.

[0018] (4) The application scheme is flexible and reliable. It can adapt to the damage assessment of turbines of different types and specifications by simply adjusting the turbines participating in the test scheme and the turbines for which the simulation model is established to the turbines to be evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is one of the flow charts of a damage mechanism assessment method based on a Francis turbine provided in an embodiment of the present application.

[0020] Figure 2 This is the second flow chart of a damage mechanism assessment method based on a Francis turbine provided in an embodiment of the present application.

[0021] Figure 3 It is a structural schematic diagram of a damage mechanism assessment system based on a Francis turbine provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0024] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two. For example, a plurality of influencing factors refers to two or more than two influencing factors, etc.

[0025] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0026] Embodiment 1: like Figure 1 The flowchart of Example 1 of the present application is shown, which includes the following steps: (1) Collect the original data of the turbine under different operating conditions and obtain the influencing factors of the operating conditions from the original data.

[0027] (21) Conduct turbine operation tests to obtain the changing relationship between influencing factors and performance indicators under normal operating conditions. Specifically include: (211) Under the premise of ensuring the normal operation of the turbine, the value of the influencing factor is used as the experimental input and the performance index of the turbine is used as the experimental output; (212) Each time the test input is changed by a preset step size, the test is repeated until all influencing factors are input, and each test input and corresponding test output are recorded; (213) Use mathematical models to describe the changing relationship between influencing factors and performance indicators.

[0028] In this process, a turbine operation test is carried out on the turbine to be evaluated.

[0029] (22) Based on the above change relationship, the significance analysis of the influencing factors is performed to obtain significant factors. Specifically including: (221) Determine the factors that have a significant impact on the performance indicators according to the significance level; (222) Ranking the impact factors with significant effects based on their impact size; (223) The factors with the greatest impact and a preset number of factors are defined as significant factors.

[0030] Among them, the influencing factors include blade inclination angle, guide vane opening, water flow velocity and water head height. Performance indicators include work efficiency, hydraulic loss and vibration noise.

[0031] (3) Establishing a simulation model of the turbine, adjusting the value of the significant factor to perform multi-physical field simulation analysis, extracting the damage of the turbine from the simulation data, and saving the value of the significant factor and the corresponding damage to the evaluation database. The evaluation database also includes: selecting the significant factor from the original data, extracting the damage of the turbine from the corresponding original data, and saving the value of the significant factor and the corresponding damage to the evaluation database.

[0032] The damage condition is specifically obtained by the following method: obtaining the pressure distribution, temperature distribution and water flow distribution when the turbine is running; and evaluating the damage location and degree of the turbine based on the pressure distribution, temperature distribution and water flow distribution.

[0033] Specifically, the simulation data includes: comparing the simulation data with the original data, and retaining the simulation data whose difference is less than a preset threshold.

[0034] Among them, a simulation model of the turbine is established using the turbine to be evaluated as a template.

[0035] (4) Obtain the values ​​of significant factors of the turbine to be evaluated in real time during operation, compare and match the values ​​of significant factors with the evaluation database, and obtain the damage status of the turbine to be evaluated.

[0036] Embodiment 2: like Figure 2 The flowchart of Example 2 of the present application is shown, which includes the following steps: Step S100 obtains original data by analyzing the turbine under different working conditions, establishes an experimental analysis plan based on the original data, performs factor significance analysis, and obtains the key influencing factors and their magnitudes on the normal operation of the turbine.

[0037] First, relevant data of the turbine under actual working conditions will be collected. These data include but are not limited to common damage conditions of the turbine, related factors leading to damage (such as blade inclination, guide vane opening, head height, etc.), and performance indicators such as turbine working efficiency. To ensure the accuracy and reliability of the data, the data will be preprocessed, including removing noise and outliers, and unifying and standardizing the data format.

[0038] Based on the collected data, a test plan is designed. The test plan will specify the test conditions, test steps and test parameters. During the test, key information such as the operating status of the turbine and changes in performance indicators will be recorded. The implementation of the test will follow scientific and rigorous principles to ensure the accuracy and reliability of the test results.

[0039] Define the research object, collect and organize the basic operating data of various types of turbines under normal operating conditions, and ensure the integrity and accuracy of the data. Analyze the data, identify and determine the key test factors that have an important impact on the performance of the turbine, such as blade inclination, guide vane opening, etc., and clarify the possible range of variation of these factors, and establish a detailed test analysis factor status table based on this. According to the design objectives and actual operating requirements of the turbine, scientifically and reasonably determine the evaluation indicators, such as work efficiency, hydraulic loss, vibration and noise, etc. These indicators can fully reflect the operating status and performance level of the turbine.

[0040] Subsequently, mathematical or physical models are used to closely link the test factors with the evaluation indicators and establish parameter equations, providing a solid theoretical basis for subsequent analysis work.

[0041] Using advanced statistical software or mathematical methods, we can reveal the way and degree of influence of each test factor on the evaluation index, and determine which factors have a significant impact on the evaluation index based on the significance level (such as P value, F value, etc.). On this basis, we can sort the influence of each factor and determine the priority, providing a scientific basis for subsequent simulation analysis, performance evaluation and maintenance management.

[0042] Step S200 establishes a turbine model, and uses advanced simulation software to perform multi-physics field simulation analysis on the simulation model to obtain the operating status and performance indicators of the turbine under different working conditions.

[0043] Based on the test results, a Francis turbine simulation model identical to the actual unit will be established. The simulation model will include key information such as the turbine's geometry, material properties, and boundary conditions. Advanced simulation software, such as CFD (Computational Fluid Dynamics) software, will be used to perform multi-physics simulation analysis on the simulation model. The simulation analysis will consider the effects of multiple physical fields such as water velocity, pressure distribution, and temperature distribution to obtain the operating status and performance indicators of the turbine under different operating conditions.

[0044] During the simulation analysis, different operating conditions are set, such as different water flow velocities and blade inclination angles, to simulate the various states of the turbine in actual operation. The simulation analysis will output a large amount of data, including water flow velocity distribution, pressure distribution, temperature distribution, etc. These data are processed and analyzed to extract key information, such as damage location and damage degree. At the same time, the basic data obtained by the sensor is compared with the simulation data to verify the accuracy and reliability of the simulation results.

[0045] Step S300 establishes a database by collecting and organizing the original data and simulating and analyzing the data obtained, and compares and analyzes the actual data obtained by the subsequent sensors to determine the damage status of the turbine.

[0046] Based on the results of simulation analysis and data processing, the damage of the turbine is evaluated. The evaluation will consider the location and extent of the damage and its impact on the performance of the turbine. Based on the evaluation results, corresponding solutions are formulated, including repair suggestions, maintenance plans and preventive measures.

[0047] Finally, a real-time monitoring system is established to use sensors to obtain the operating data of the turbine in real time. These data will be compared with the historical data in the database to monitor the damage of the turbine in real time. When abnormal data is found, the system will issue an early warning message to remind the operator to take timely measures. At the same time, based on the real-time data obtained, the prediction model is used to predict the future operating status of the turbine to detect potential damage in advance and take corresponding preventive measures.

[0048] Embodiment 3: like Figure 3 The figure shows a schematic diagram of the structure of a damage mechanism assessment system based on a Francis turbine according to an embodiment of the present application, which specifically includes: A data collection module is used to collect raw data of the turbine under different working conditions and obtain the influencing factors of the working conditions from the raw data; The test analysis module is used to conduct a turbine operation test, obtain the change relationship between the influencing factors and the performance indicators under normal working conditions, and perform a significance analysis on the influencing factors based on the change relationship to obtain significant factors; The simulation analysis module is used to establish a simulation model of the turbine, adjust the value of the significant factor to perform multi-physics field simulation analysis, extract the damage of the turbine from the simulation data, and save the value of the significant factor and the corresponding damage to the evaluation database; The damage assessment module is used to obtain the values ​​of significant factors of the turbine to be assessed in real time during operation, compare and match the values ​​of the significant factors with the assessment database, and obtain the damage status of the turbine to be assessed.

[0049] It should be understood that the above-mentioned system is used to execute the methods in the above-mentioned embodiments. The implementation principles and technical effects of the corresponding modules in the system are similar to those described in the above-mentioned methods. The working process of the system can refer to the corresponding process in the above-mentioned method and will not be repeated here.

[0050] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0051] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A damage mechanism assessment method based on a Francis turbine, characterized in that: The damage mechanism assessment method includes: Collect the original data of the turbine under different working conditions and obtain the influencing factors of the working conditions from the original data; Conducting a turbine operation test to obtain the changing relationship between the influencing factors and the performance indicators under normal working conditions, and performing a significance analysis on the influencing factors based on the changing relationship to obtain significant factors; Establish a simulation model of the turbine, adjust the value of the significant factor to perform multi-physics field simulation analysis, extract the damage of the turbine from the simulation data, and save the value of the significant factor and the corresponding damage to the evaluation database; The values ​​of significant factors of the turbine to be evaluated are obtained in real time during operation, and the values ​​of significant factors are compared and matched with the evaluation database to obtain the damage status of the turbine to be evaluated.

2. The damage mechanism assessment method according to claim 1, characterized in that: Conduct turbine operation tests to obtain the changing relationship between influencing factors and performance indicators under normal working conditions, specifically: Under the premise of ensuring the normal operation of the turbine, the value of the influencing factor is used as the experimental input, and the performance index of the turbine is used as the experimental output; Each time, the test input is changed with a preset step size, and the test is repeated until all influencing factors are input, and each test input and corresponding test output are recorded; Use mathematical models to describe the changing relationship between influencing factors and performance indicators.

3. The damage mechanism assessment method according to claim 1, characterized in that: Based on the change relationship, a significance analysis is performed on various influencing factors to obtain significant factors; Determine the influencing factors that have a significant impact on the performance indicators according to the significance level; Ranking the impact factors with significant influence based on their impact size; The influencing factors with the greatest impact are defined as significant factors.

4. The damage mechanism assessment method according to claim 1, 2 or 3, characterized in that: The influencing factors include blade inclination angle, guide vane opening, water flow velocity and water head height.

5. The damage mechanism assessment method according to claim 1, 2 or 3, characterized in that: The performance indicators include work efficiency, hydraulic loss and vibration noise.

6. The damage mechanism assessment method according to claim 1, characterized in that: The evaluation database also includes: selecting significant factors from the original data, extracting damage conditions of the turbine from the corresponding original data, and saving the values ​​of the significant factors and the corresponding damage conditions to the evaluation database.

7. The damage mechanism assessment method according to claim 1 or 6, characterized in that: The damage condition is specifically obtained by the following method: obtaining the pressure distribution, temperature distribution and water flow distribution when the turbine is running; and evaluating the damage position and damage degree of the turbine based on the pressure distribution, temperature distribution and water flow distribution.

8. The damage mechanism assessment method according to claim 1, characterized in that: The simulation data specifically includes: comparing the simulation data with the original data, and retaining the simulation data whose difference is less than a preset threshold.

9. The damage mechanism assessment method according to claim 1, characterized in that: A hydraulic turbine operation test is carried out on the hydraulic turbine to be evaluated; and a hydraulic turbine simulation model is established using the hydraulic turbine to be evaluated as a template.

10. A damage mechanism assessment system based on a Francis turbine, characterized in that: The damage mechanism assessment system comprises: A data collection module is used to collect raw data of the turbine under different working conditions and obtain the influencing factors of the working conditions from the raw data; The test analysis module is used to conduct a turbine operation test, obtain the change relationship between the influencing factors and the performance indicators under normal working conditions, and perform a significance analysis on the influencing factors based on the change relationship to obtain significant factors; The simulation analysis module is used to establish a simulation model of the turbine, adjust the value of the significant factor to perform multi-physics field simulation analysis, extract the damage of the turbine from the simulation data, and save the value of the significant factor and the corresponding damage to the evaluation database; The damage assessment module is used to obtain the values ​​of significant factors of the turbine to be assessed in real time during operation, compare and match the values ​​of the significant factors with the assessment database, and obtain the damage status of the turbine to be assessed.

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